Clutch.



F.G.SANF0RD.

CLUTCH.

-APPL IOATION IILE 910. 981,885. Patented Jan.17,1911.

WITNESSES:

I an STATES 'ATENT, OFFICE.

FRANK C. SANFORD, IBBIDGEPORT,CONNECTICUT.

CLUTCH.

Specification of Letters Patent. Application filed April 16, 1910. Serial no. 555,887.

Patented Jan. 17, 1911.

To all whom it may concern: Be it known that I, FRANK C. SANFORD, a citizen of the United States, residing at Bridgeport, county of Fairfield, and State of itappertainsto make and use the same.

My invention has reference to certainim provements in clutches,- and has for its object i a sectional elevation! illustrating my imto so combine a friction clutch and a positive clutch that the latter will be brought into operation without the slightest jar or shock, thus doing away with the disadvantages incident to the use of positive clutches.

With these ends in view my invention consists in thecombination and arrangement of parts hereinafter fully set forth and then particularly pointed out in the claims which conclude this description.

In the accompanying-drawing Figure 1 is provement; and Fig.2 a section at the line w, c2, of Fig. 1. l

Similar numerals ofr'eference denote like parts in both figures of the drawing.

The chief disadvantage that has been incidental to the use of a positive clutch Where the engagement of the clutch elements is instantaneous, is that such engagement is accompanied by more or less shock and jar, which, in many kinds'ofwork, causes chatters or other imperfections and bad results. A friction clutch overcomes these disadvantages to a considerable degree, but the tr'ouble; with such a clutch is that there is usually more -or less slipping between the driving and the driven elements. which not only causes the engaging surfaces to become rapidly worn away, but .in some-instances theslipping is so pronounced that work on the machine cannot be properly. rform'ed or effected with sufiicleiit expe ition. It is;

therefore quite advantageous to "so combine these two sets of clutches that all the ad; vantages .of a friction clutch are preserved, 1 while the engagement of the positive driving and positive driven elements is effected with-,

out theslightest jar or shock, all of which will be understood from the following" description.

4 .1. is the power shaft and a hollow head loosely supported around said shaft in any suitable and ordinary manner. In the pressuitable and approved manner.

7 is a divided friction ring yvhich closely conforms to the internal contour of the head r without normally binding thereagai-nst, and this ring has a, hub portion 8 which surrounds the shaft 1 and is rigidly secured thereto by means of a key 9.

10 are toggle levers pivoted at their outer extremities to o posite edges of said ring on one side of t e split which divides the latter and 11 are similar toggle levers piv oted to opposite edges of such'ring onthe other side of said split, and the inner ex-' tremities of said levers are all pivoted around a pin 12 which extends in a plane immediately below said split. Tight on said pin and intermediate of said toggle is a. block 13 having. itslower surfacewedge shaped, ,which block is contained within a gate 14 at the upper portion of an extension 15 fromthehub 8. I

. The ring 7 does not completely the hollowpart of the head 2, but-1n the immediate rear of said ring a space or recess 16 is left, and back ofthis recess the head is provided, with slots 17 which open into said recess, and within these slots are plvoted dogs 18 whose-forward extremitles normally project through said slots .into said recess.

of the ring 7 are pins 20, 21. The pin 20 has 1 a beveled surface which engages the beveled surface of the block 1 3 when the collar is forced inwardly toward -the head 2, thereby 0' crating the tog les to effect the spreading o 'the ring 7 and the consequent fr1ct1onal engagement thereof with said head whereby the lattenmay be revolved; the pm 21,

when the collar is forced inwardly toward the head 2, will be projected within the recess 16 and would ordinarilybe carried all around throughout the entire circuit of this recess owing to the slipping between the friction clutch and the head, but, in the present instance, the speed at which the head is driven will cause the dogs 18 to be thrown outwardly by centrifugal force within the path of travel of this pin 21, so-that when the latter finally overtakes one of said dogs it will come into engagement therewith without the slightest jar or shock, and thereafter the head will be driven positively.

If desired, a light spring 22, contained within a suitable perforation 23 in the hub portion of the head and backed by a tension controlling screw 24 and bearing against the dogs, may be employed to render the latter more or less susceptible to centrifugal force as illustrated in the instance of one of the dogs at Fig. 1, but this is merely an adjunctive feature and is in the nature of a device fully within 'the range of ordinary mechanical skill and forms no part of my present invention.

The power pulley is not illustrated herein,

since it forms no part of my inventionand may be secured to thehead 2 in any suitable and ordinary manner.

While I have illustrated in-the drawings two dogs which serve as the positive abutting elements carried by the head, it will be clearthat one dog is suflicient for the purpose of my invention, or the number of'these dogs may even be increased if desired, and I do not desire to be limited in this respect although I prefer to use'a pair of dogs slnce the engagement of the positive abutting surfaces is apt to be accomplished more quickly,

and, moreover, if one dog should break or becomeinoperative for any reason, the re- .maining dog would always insure a proper clutching of the positive abutting elements.

I have shown and described a style of friction clutch which is old and well known, and in this connection I would say that any suitable conventional form of friction clutch would sub'serve the purposes of my invention, the gist of which rests inthe broad idea of combining a friction clutch with a 'posithe clutch. I

Instead of employing a single shaft l with the head loosely supported therearound, said shaft may be divided, as, for instance,- at the dotted line a, shown at Fig. 1, and said head then rigidly secured to the rear section of said shaft as by a key shown at b in dotted lines in said figure, such a construction being a mechanical equivalent well within the province of my invention.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A clutch comprising a power shaft, a hollow rotary head loose on said shaft, a slidable collar revolving with said shaft, a friction clutch carried by said shaft, means carried by said collar whereby the sliding of the latter will cause said clutch to engage with anddisengage from said head, dogs pivoted within said head and capable of free movements from their pivotal points whereby they may beflthrown outwardly by centrifugal force, and an element operated by said collar and adapted to be thrust within or withdrawn from the field of said dogs.

2. A clutch comprising a power shaft, a hollow rotary head loose on said shaft, a friction clutch carried by said shaft within said head, positive abutting devices pivoted within said head and capable of free movements from their pivotal points whereby they may be thrown outwardly by centrifugal force, means carried by said shaft and .operated to cause theengagement of said friction clutch and head, and an element likewise carried by said shaft into position for impact against said abutting devices.

3. A clutch comprising a power shaft, a

hollow rotary head loose on said shaft, a

slidable collar revolving with said shaft, a

friction clutch carried by said shaft, means carried by said collar for-operating said friction clutch, an abutting element carried by said collar and adapted thereby to be forced inwardly, and an abutment pivoted within said head and capable of free movements from its pivotal point whereby it may be.

thrown outwardly by centrifugal force in the path of said abutting element whereby said head may be positively driven.

LA clutch comprising a power shaft, a hollow rotary head loose on said shaft, a slidable collar revolving with said shaft, a friction clutch carried by said collar for operating said friction clutch, an abutting element carried bysaid collar and partaking of the movements thereof, and an abutment carried by said head and rigid therewith as to rotary movements but capable. of radial movements with respect to said shaft whereby said abutment may bethrown outwardly by centrifugal force in the path of said abutting element.

In testimony whereof I affix my signature in presence of two witnesses.

c. SANFORD. 

